The measurement accuracy of a fuel dispenser is critical as a measuring instrument. In the practice of some fuel dispensers, the measurement accuracy does not meet the requirements for the artificial or non-human actions of stealing oil and oil leakage.
The artificial behaviors of stealing oil and oil leakage are fraudulent activities. The means of the fraud practices mainly are there in the common cases as the following:                (1) Modify the measuring software to fraud, such as changing the pulse equivalent of measuring software,        (2) Fraud in pulse signal transmission channels, such as inserting pulse signals in them.        (3) Fraud in pulse signal sources: sending more pulse signals, such as actually generating 100 pulses, but the intelligent component issues 110 pulses. For the non-human activities of stealing oil and oil leakage, there are kinds of following cases very often:        (1) Fuel dispenser component failures, such as the electromagnetic valve failure;        (2) Interfering signals occur in the pulse transmission process of the fuel dispensers,        (2) Fuel dispenser cable connection is not correct, that is generally caused by maintenances.        
In view of these defects, and no effective ways to prevent these acts, this inventor finally got to invent a security pulse generator for fuel dispensers and its anti-fraud methods after a long time of researches and practices,